The normal value of blood potassium is 3.5-5.5 mmol/L. Blood potassium is an important ion for maintaining the cardiovascular system and neuromuscular excitability, and it is important to maintain the normal functioning of the body only if the blood potassium is within the normal range, not if it is too low or too high. If the blood potassium level is lower than 3.5 mmol/L, it is hypokalemia, which is common in patients with long-term poor diet and diuretics, and needs to be supplemented with potassium chloride extended-release tablets or potassium chloride injection so that the symptoms of hypokalemia will improve. If the blood potassium concentration exceeds 5.5 mmol/L, the blood is hyperkalemic, which is common in diseases such as acidosis, and diuretics should be used to limit the intake of potassium salts. If necessary, hypertonic glucose and insulin can be titrated, and sodium bicarbonate injection can also be applied to lower the blood potassium.